Parallel Cross-Entropy Optimization

The cross-entropy (CE) method is a modern and effective optimization method well suited to parallel implementations. There is a vast array of problems today, some of which are highly complex and can take weeks or even longer to solve using current optimization techniques. This paper presents a general method for designing parallel CE algorithms for multiple instruction multiple data (MIVID) distributed memory machines using the message passing interface (MPI) library routines. We provide examples of its performance for two well-known test-cases: the (discrete) Max-Cut problem and (continuous) Rosenbrock problem. Speedup factors and a comparison to sequential CE methods are reported

Information Sharing and Cooperative Search in Fisheries

We present a dynamic game of search and learning about the productivity of com-peting fishing locations. Perfect Bayesian Nash equilibrium search patterns for non-cooperating fishermen and members of an information sharing cooperative are com-pared with first-best outcomes. Independent fishermen do not internalize the full valueof information, and do not replicate first-best search. A fishing cooperative faces afree-riding problem, as each coop member prefers that other members undertake costlysearch for information. Pooling contracts among coop members may mitigate, butare not likely to eliminate free riding. Our results explain the paucity of informationsharing in fisheries and suggest regulators use caution in advocating cooperatives as asolution to common pool ineffciencies in fisheries.�search; Information sharing; Dynamic Bayesian game; Fishing cooperative

Rounding in Recreation Demand Models: A Latent Class Count Model

A commonly observed feature of visitation data, elicited via a survey instrument, is a greater propensity for individuals to report trip numbers that are multiples of 5's, relative to other possible integers (such as 3 or 6). One explanation of this phenomenon is that some survey respondents have difficulty recalling the exact number of trips taken and instead choose to round their responses. This paper examines the impact that rounding can have on the estimated demand for recreation and the bias that it may induce on subsequent welfare estimates. We propose the use of a latent class structure in which respondents are assumed to be members of either a nonrounding or a rounding class. A series of generated data experiments are provided to illustrate the range of possible impacts that ignoring rounding can have on the estimated parameters of the model and on the welfare implications from site closure. The results suggest that biases can be substantial, particularly when then unconditional mean number of trips is in the range from two to four. An illustrative application is provided using visitation data to Saylorville Lake in central Iowa.recreation demand; count data; rounding

Status and control of nutria in California

Although feral nutria (Myocastor coypus) have been present in California since the mid-1940's, they are quite scarce and at present are causing little or no agricultural damage. Present state regulations and pest detection activities will probably prevent them from becoming a serious economic pest. Should control ever become necessary, studies in other areas indicate that shooting, trapping, and baiting with zinc phosphide should be effective

A Minimal SU(5) SuperGUT in Pure Gravity Mediation

The lack of evidence for low-scale supersymmetry suggests that the scale of supersymmetry breaking may be higher than originally anticipated. However, there remain many motivations for supersymmetry including gauge coupling unification and a stable dark matter candidate. Models like pure gravity mediation (PGM) evade LHC searches while still providing a good dark matter candidate and gauge coupling unification. Here, we study the effects of PGM if the input boundary conditions for soft supersymmetry breaking masses are pushed beyond the unification scale and higher dimensional operators are included. The added running beyond the unification scale opens up the parameter space by relaxing the constraints on $\tan\beta$. If higher dimensional operators involving the SU(5) adjoint Higgs are included, the mass of the heavy gauge bosons of SU(5) can be suppressed leading to proton decay, $p\to \pi^0 e^+$, that is within reach of future experiments. Higher dimensional operators involving the supersymmetry breaking field can generate additional contributions to the A- and B-terms of order $m_{3/2}$. The threshold effects involving these A- and B-terms significantly impact the masses of the gauginos and can lead to a bino LSP. In some regions of parameter space the bino can be degenerate with the wino or gluino and give an acceptable dark matter relic density.Comment: 37 pages, 27 figure

The Law of Options

Little attention is devoted to the law of options in major Canadian texts on contract law or in periodical literature. One might, therefore, assume that the law in this area is well settled and that few major cases come before the courts. However, a review of appellate decisions in Canada indicates significant judicial interest in the topic which would challenge those assumptions. In fact, appellate courts in various common law jurisdictions continue to struggle with many doctrinal issues related to this specialized type of contract. This article provides a comprehensive review of the law of options in Canada, and identifies and discusses a number of the current doctrinal debates. In particular, it reviews and challenges certain fundamental doctrinal changes that appear to have been made by the Supreme Court of Canada in Sail Labrador v The Challenge One. The author suggests an alternative basis on which the Court could have achieved the same result while preserving the commercial certainty requirements which underlie the core of option law

Defamation in Broadcasting

The law of defamation is not new to the world, nor limited to certain nations: Moses commanded: Neither shalt thou bear false witness against thy neighbour. The Far East punished slander. The Twelve Tables of Rome recognized defamation. Early Anglo- Saxon and Germanic laws took a serious view of insult by word or gesture. Punishment included excision of the tongue. In England, a book on libel was written three hundred years ago. Under a French ordinance of the past century the publication of a libel was punished by whipping and on a second offence with death. \u27 Obviously, the consequences -have changed over the years, but the basic responsibility is still present. The early development of the law of defamation dealt largely with slander, and with libel in a very limited context - mostly in relation to letters and other similar communications. The advent of the printing press and the rise of newspapers saw the law flourish and grow into the large body of doctrine that we know today. The advent of modem means of telecommunication brought the scope of that law to unthought of application in the modem world. This article will examine the nature of the medium and the application of the centuries old concepts of defamation to radio and television broadcasting. The article is by no means exhaustive, as to cover every aspect of defamation and its application to broadcasting would be a phenomenal task. Instead, several aspects of the law will be examined to see how the courts adapted the old concepts to the new medium and to point out any needed changes in the law. The relevant legislation in the area and the special problems arising in a federal state will be examined, namely the constitutional and conflict of laws problems

Scenarios for Gluino Coannihilation

We study supersymmetric scenarios in which the gluino is the next-to-lightest supersymmetric particle (NLSP), with a mass sufficiently close to that of the lightest supersymmetric particle (LSP) that gluino coannihilation becomes important. One of these scenarios is the MSSM with soft supersymmetry-breaking squark and slepton masses that are universal at an input GUT renormalization scale, but with non-universal gaugino masses. The other scenario is an extension of the MSSM to include vector-like supermultiplets. In both scenarios, we identify the regions of parameter space where gluino coannihilation is important, and discuss their relations to other regions of parameter space where other mechanisms bring the dark matter density into the range allowed by cosmology. In the case of the non-universal MSSM scenario, we find that the allowed range of parameter space is constrained by the requirement of electroweak symmetry breaking, the avoidance of a charged LSP and the measured mass of the Higgs boson, in particular, as well as the appearance of other dark matter (co)annihilation processes. Nevertheless, LSP masses $m_\chi \lesssim 8$~TeV with the correct dark matter density are quite possible. In the case of pure gravity mediation with additional vector-like supermultiplets, changes to the anomaly-mediated gluino mass and the threshold effects associated with these states can make the gluino almost degenerate with the LSP, and we find a similar upper bound.Comment: 25 pages, 22 figure